title: A rapid and simple chromatographic separation of diastereomers of silibinin and their oxidation to produce 2,3-dehydrosilybin enantiomers in an optically pure form.
abstract: Silybin A and B were separated from commercial silibinin using the preparative HPLC method. The described method is rapid and effective in obtaining gram-scale amounts of two diastereoisomers with minimal effort. In our approach, silibinin was dissolved in THF (solubility greater than 100 mg/mL), an alternative solvent to H₂O or MeOH in which silibinin has a very low solubility (ca 0.05-1.5 mg/mL), and then separated into its two components using preparative RP-HPLC. By starting with purified diastereoisomers, it was possible to obtain the two enantiomers of 2,3-dehydrosilybin in good yields and optically pure using an efficient oxidation procedure. All of the purified products were fully characterised using NMR (¹H, ¹³C), CD, [α](D), and ESI MS analyses. The purities of the products, which were evaluated using analytical HPLC, were greater than 98% in all cases.
authors.affiliation: Department of Chemical Sciences, University of Napoli 'Federico II', Napoli, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Fabio
authors.forename: Valeria
authors.initials: V
authors.lastname: Romanucci
authors.forename: Cinzia
authors.initials: C
authors.lastname: Di Marino
authors.forename: Lorenzo
authors.initials: L
authors.lastname: De Napoli
authors.forename: Armando
authors.initials: A
authors.lastname: Zarrelli
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D020944:Silybum marianum / Q000737:chemistry*; D010084:Oxidation-Reduction; D000077385:Silybin; D012838:Silymarin / Q000737:chemistry / Q000302:isolation & purification*; D013237:Stereoisomerism
chemical_list: D000975:Antioxidants; D012838:Silymarin; C515097:dehydrosilybin; D000077385:Silybin